Integrating sphere method for determining the effective spectral emissivity of superalloys at high temperatures using a single wavelength pyrometer

Abstract

A method that employs an integrating sphere and a single‐wavelength (1.6‐μm) pyrometer for measuring the spectral effective emissivities of superalloys in the temperature range (∼650 to 1050 °C) is described. The spectral effective emissivities for five superalloys, namely, MARM‐247, MARM‐509, CMSX‐4, Inconel‐718, and N‐155 were measured. Correcting the pyrometer measurements for the variations in the object emissivity would reduce the uncertainty in the temperature measurements to <±1%. © 1996 Society of Photo−Optical Instrumentation Engineers.